1. Field of the Invention
The present invention relates to a semiconductor integrated circuit device having circuit blocks.
2. Background Art
FIG. 19 shows a conventional type of semiconductor integrated circuit device IC1 having circuit blocks. Specifically, the semiconductor integrated circuit device IC1 has two circuit blocks: a processing unit (CPU) 1 and a read-only memory (ROM) 3. The circuit blocks 1 and 3 are formed away from each other on a same semiconductor substrate SC1; the ROM 3 is formed to the left of the CPU 1. The CPU 1 and ROM 3 are electrically connected to each other by a plurality of wires 4 so that the CPU 1 can read data from the ROM 3 as necessary. A plurality of bonding pads 5 are disposed along the right and left edges of the semiconductor substrate SC1. The bonding pads 5 are electrically connected to the CPU 1 and the ROM 3 by the wiring layer on the semiconductor substrate SC1. The bonding pads 5 are also electrically connected to external leads (not shown) of the semiconductor integrated circuit device IC1 by bonding wires (not shown) so that the CPU 1 and the ROM 3 can receive and output signals through the external leads.
FIG. 20 shows another conventional type of semiconductor integrated circuit device IC2 in which a random access memory (RAM) 2 is added to the structure of the semiconductor integrated circuit device IC1 of FIG. 19 as a third circuit block. In the semiconductor integrated circuit device IC2, the CPU 1 is formed at the center on a semiconductor substrate SC2 with the ROM 3 and the RAM 2 formed on its left and right sides respectively. The CPU 1 and the ROM 3 are electrically connected to each other by a plurality of wires 4, while the CPU 1 and the RAM 2 are electrically connected to each other by a plurality of wires 6. The CPU 1 retrieves information from the RAM 2 through the wires 6 as well as supplies information to the RAM 2 for storage, as necessary. The bonding pads 5 are disposed along the right and left edges of the semiconductor substrate SC2, as in FIG. 19, and used to exchange signals among the external leads, the CPU 1, the RAM 2, and the ROM 3.
Consider an attempt to produce the semiconductor integrated circuit device IC2 by modifying the semiconductor integrated circuit device IC1. With prior art techniques, it is difficult to add the RAM 2 (another circuit) to the semiconductor integrated circuit device IC1 with its CPU 1 and ROM 3 intact. Therefore, conventionally, the semiconductor integrated circuit device IC2 (the another type of semiconductor integrated circuit device) shown in FIG. 20 is newly produced separately from the semiconductor integrated circuit device IC1 shown in FIG. 19. This means that even though the semiconductor integrated circuit device IC2 shown in FIG. 20 includes the CPU 1 and the ROM 3 common to the semiconductor integrated circuit device IC1 shown in FIG. 19, the semiconductor integrated circuit device IC2 must be newly developed, designed, and manufactured independently of the semiconductor integrated circuit device IC1, incurring additional development and design cost.
The present invention has been devised to solve the above problems. It is, therefore, a first object of the present invention to propose an improved semiconductor integrated circuit device employing common circuit blocks in such a way that another type of semiconductor integrated circuit device can easily be manufactured from the improved semiconductor integrated circuit device.
A second object of the present invention is to propose an improved semiconductor integrated circuit device employing common circuit blocks in such a way that it can easily be manufactured from another type of semiconductor integrated circuit device.
According to one aspect of the present invention a semiconductor integrated circuit device comprises a semiconductor substrate; a circuit block on the substrate; a plurality of bonding pads disposed around the circuit block, being connected to external leads of the semiconductor integrated circuit device; and a plurality of wires extended from the circuit block into space between the bonding pads, each wire having a shape connectable to another wire.
When another circuit block is provided on the main surface of the semiconductor integrated circuit device, the plurality of wires which are extended from the circuit block into the space between the bonding pads can be connected to the wires of the another circuit block since the plurality of wires have such a shape that they are connectable to the wires of the another circuit block. With this arrangement, it is possible to dispose both a circuit block and another circuit block on a common semiconductor substrate with a distance therebetween and connect their wires together. Therefore, based on a semiconductor integrated circuit device having at least one circuit block, another type of semiconductor integrated circuit device can be easily manufactured by utilizing the circuit block, its bonding pads, and wires.
According to another aspect of the present invention a semiconductor integrated circuit device comprises a semiconductor substrate; a main circuit block and a sub-circuit block disposed alongside of each other with a distance therebetween on the substrate; a plurality of bonding pads disposed between the main circuit block and the sub-circuit block, being connected to external leads of the semiconductor integrated circuit device; a plurality of first wires extended in a direction from the main circuit block to the plurality of bonding pads, preferably extended from the main circuit block into space between the plurality of bonding pads; and a plurality of second wires extended from the sub-circuit block and each electrically connected to one of the first wires.
Since the plurality of bonding pads are disposed between the main circuit block and the sub-circuit block, the sub-circuit block can be disposed outside of the bonding pads around the main circuit block. With this arrangement, the sub-circuit block and the main circuit block can be easily formed alongside of each other on a same semiconductor substrate. As a result, it is possible to easily form a plurality of semiconductor integrated circuit devices of different types employing a common main circuit block. Furthermore, as described above, the plurality of first wires are extended in a direction from the main circuit block to the plurality of bonding pads, for example extended from the main circuit block into the space between the bonding pads, and the plurality of second wires are electrically connected to the first wires. With this arrangement, it is possible to electrically connect the main circuit block and the sub-circuit block with ease.
Other and further objects, features and advantages of the invention will appear more fully from the following description.